On April 19, 1973, Rosemarie D'Alessandro's daughter, Joan, said "Goodbye, Mommy," as she ran out the door. Joan was a Brownie Scout, and she was excited about delivering the last two boxes of Girl Scout cookies to a neighbor. Her mother didn't know it would be the last time that she would see her seven-year-old child alive. Her neighbor sexually assaulted and brutally murdered her joyful little girl.

The crime stunned the suburban community of Hillsdale, New Jersey, and the entire nation. The emphasis on child safety changed overnight. Rosemarie was numb with grief, but she was able to get some peace and solace by her belief that there was a hopeful message in the significant days Joan was killed and found.

Twenty years later, when her killer shockingly had a chance to get out of prison, she started a grassroots movement and the community united together to get over one hundred thousand signatures opposing his parole. Rosemarie saw that laws had to be changed to stop the injustice that her family had to go through. Her efforts led to the passage of five laws on the state and federal level that would help to protect children and give victims more rights.

An unimaginable turn of events took place when a man brought her 332 letters that Joan's killer wrote. After he died in 2021, Rosemarie felt free to share all the letters in their entirety, which gives the listener a rare opportunity to see inside the mind of a killer. In this book, The Message of Light amid Letters of Darkness, the letters are included with Rosemarie's summaries and comments, and she tells the parallel story of her life and activism during the time period the letters were written.

Her story shows the power of the human spirit as Rosemarie finds a way to make something hopeful out of horrendous tragedy. She perseveres to go for what she believes in despite unexpected obstacles and hardships. She doesn't let hate and animosity take her down, freeing her to go forward and become Joan's voice.